Muscles Flashcards
What is the sacroplasm?
Cytoplasm of the muscle, contains large amounts of glycogen
What protein in the sarcoplasm stores oxygen?
Myoglobin —> iron containing protein, high affinity for oxygen
What storage carbohydrate is stored in the sarcoplasm? What other organ in the body stores this compound?
Glycogen; the Liver stores it
What are myofibrils?
Contain protein filaments that are responsible for muscle contractile ability —> proteins include: actin, myosin, titin, and others
What is the sarcolemma?
The plasma membrane of the muscle cell —> regulates ion exchange across cell
What role do T-tubules serve?
They are invaginations of the sarcolemma that penetrate into the muscle fiber to help actions potentials reach the entirety of the muscle fiber
What is the role of the sarcoplasmic reticulum?
Stores calcium ions (critical for muscle contraction); action potentials that propagate along the sarcolemma will result in the release of calcium from the sarcoplasmic reticulum
What are Sarcomeres?
Fundamental contractile unit of a muscle fiber
What’s the Z-disk or Z-line?
Muscle fibers are made up of actin and Z disks are overlapping ends of actin filaments from adjacent sarcomeres
What are the thin filaments of the sarcomere?
I band
What are the thick filaments of the sacromere?
A bind
What proteins is wrapped around the thin filaments and blocks binding sites?
Tropomyosin; prevents contraction
What proteins, when bounded by calcium, moves this protein off of the binding sites?
Troponin when bounded by calcium undergoes a conformational change and moves tropomyosin off the myosin binding site
What protein connects to Z disks to M bands?
Titin
What are the three types of muscle tissue; which two are striated?
Smooth, cardiac, and skeletal; skeletal and cardiac